Secondary battery manufacturing system for simplifying process of manufacturing unit cells by laminating and process of forming electrode assembly using unit cells

ABSTRACT

Provided is a secondary battery manufacturing system which includes: a unit cell forming device for the forming unit cells, in which a separator, an anode cell, a separator, a cathode cell, and a separator are stacked in order, from a separator roll, an anode cell roll, and a cathode cell roll, which are rolled; an inverting device for forming inverted unit cells, in which a separator, a cathode cell, a separator, an anode cell, and a separator are stacked in order, by inverting some of two or more unit cells formed by the unit cell forming device; and a stacking device for stacking a unit cell, an anode cell, an inverted unit cell, and a cathode cell in order, in which the process of manufacturing an electrode assembly is simplified, and the defect rate of the manufactured electrode assembly is lowered.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to a secondary battery manufacturingsystem for simplifying a process of manufacturing unit cells bylaminating and a process of forming an electrode assembly using the unitcells, and more specifically, to a secondary battery manufacturingsystem for simplifying a process of manufacturing unit cells bylaminating and a process of forming an electrode assembly using the unitcells, which makes it easy to manufacture the unit cells by laminatingand manufacture the electrode assembly by alternately stacking the unitcells and inverted unit cells.

Background of the Related Art

Rechargeable secondary batteries are widely used as an energy source ofa mobile device. In addition, the secondary batteries are used as anenergy storage means of an electric vehicle or the like, which isproposed as a solution for solving the problem of exhaustion gas ofinternal combustion engines and the problem of fossil fuel depletion.

The secondary batteries are classified into a cylindrical cell, aprismatic cell, and a pouch cell according to external and internalstructural features.

An electrode assembly of a structure including a cathode, a separator,and an anode constituting a secondary battery is largely classified as ajelly-roll type (rolling type) or a stack type (stacking type) accordingto its structure. The jelly-roll type electrode assembly is manufacturedby coating, drying and pressing an electrode active material or the likeon a metal foil used as a current collector, tailoring the metal foil inthe form of a band having a desired width and length, separating theanode from the cathode using a separator, and rolling the metal foil ina spiral form.

Although a jelly-roll type electrode assembly may be preferably used ina cylindrical battery, when it is applied to a prismatic or pouch typebattery, the electrode active material is peeled off as the stress islocally concentrated, or deformation of the battery is induced due tothe contraction and expansion phenomenon repeated in the charge anddischarge process.

On the other hand, a stack type electrode assembly is a structuresequentially stacking a plurality of cathode and anode unit cells, andhas an advantage of easily obtaining a prismatic shape. However, it is adisadvantage in that the manufacturing process is complicated, and whenan impact is applied, the electrode is pushed, and a short circuitoccurs.

To solve this problem, some of prior art techniques have proposed astack and folding type electrode assembly, which has a structure foldinga full cell having a structure of a cathode, a separator and an anode ora bicell having a structure of a cathode (anode), a separator, an anode(cathode), a separator, and a cathode (anode) using a long continuousseparation film, as a hybrid electrode assembly combining the jelly-rolltype and stack type electrode assemblies.

However, the stack and folding type electrode assembly isdisadvantageous in that an internal space or system for themanufacturing process of arranging unit cells in a long sheet-typeseparator one by one and folding the unit cells and the separator byholding both ends are essentially required, and the process is verycomplicated, and as a result, the facility investment cost is high.Furthermore, as the number of unit cells increases, the unit cells aredifficult to roll as they are arranged in a row, and thus, the defectrate of the electrode assembly may increase.

SUMMARY OF THE INVENTION

Therefore, the present invention has been made in view of the aboveproblems, and it is an object of the present invention to provide asecondary battery manufacturing system for simplifying a process ofmanufacturing unit cells by laminating and a process of forming anelectrode assembly using the unit cells, which can lower the defect rateof the manufactured electrode assembly and can be used for manufacturingthe electrode assembly.

To accomplish the above object, according to one aspect of the presentinvention, there is provided a secondary battery manufacturing systemfor simplifying a process of manufacturing unit cells by laminating anda process of forming an electrode assembly using the unit cells, thesystem comprising: a unit cell forming device for the forming unitcells, in which a separator, an anode cell, a separator, a cathode cell,and a separator are stacked in order, from a separator roll, an anodecell roll, and a cathode cell roll, which are rolled; an invertingdevice for forming inverted unit cells, in which a separator, a cathodecell, a separator, an anode cell, and a separator are stacked in order,by inverting some of two or more unit cells formed by the unit cellforming device; and a stacking device for stacking a unit cell, an anodecell, an inverted unit cell, and a cathode cell in order, wherein theunit cell forming device forms the unit cells by stacking andintegrating a separator, an anode cell, and a separator in order, andthen stacking and integrating a cathode cell and a separator thereon.

To accomplish the above object, according to one aspect of the presentinvention, there is provided a secondary battery manufacturing systemfor simplifying a process of manufacturing unit cells by laminating anda process of forming an electrode assembly using the unit cells, thesystem comprising: a unit cell forming device for the forming unitcells, in which a separator, an anode cell, a separator, a cathode cell,and a separator are stacked in order, from a separator roll, an anodecell roll, and a cathode cell roll, which are rolled; an invertingdevice for forming inverted unit cells, in which a separator, a cathodecell, a separator, an anode cell, and a separator are stacked in order,by inverting some of two or more unit cells formed by the unit cellforming device; and a stacking device for stacking a unit cell, an anodecell, an inverted unit cell, and a cathode cell in order, wherein theunit cell forming device forms the unit cells by stacking andintegrating a separator, a cathode cell, and a separator in order, andthen stacking and integrating an anode cell and a separator below.

In addition, the unit cell forming device may include: guides forguiding the separator, the anode cell and the cathode cell unrolled fromthe separator roll, the anode cell roll, and the cathode cell roll to beoverlapped; an anode cell cutter for forming unit anode cells bydividing the anode cell in a unit size, and cutting the anode cell to bearranged at appropriate intervals; a cathode cell cutter for formingunit cathode cells by dividing the cathode cell in a unit size, andcutting the cathode cell to be arranged at appropriate intervals; afirst laminator and a second laminator for stacking and integrating theseparator, the unit anode cells arranged at appropriate intervals, theseparator, the unit cathode cells arranged at appropriate intervals, andthe separator in order; and a unit cell cutter for cutting theseparator, the unit anode cells arranged at appropriate intervals, theseparator, the unit cathode cells arranged at appropriate intervals, andthe separator integrated by the first laminator and the second laminatorin a unit cell size.

In addition, an idle roller for guiding the integrated separator, unitanode cells arranged at appropriate intervals, separator, unit cathodecells arranged at appropriate intervals, and separator from the secondlaminator to the unit cell cutter may be located between the secondlaminator and the unit cell cutter.

In addition, the inverting device may include: a conveyor beltcontinuously supplied with the unit cells; an adsorption drum located onthe top surface of the conveyor belt to adsorb the unit cells; a tablelocated at one side on the top of the adsorption drum to receive theunit cells from the adsorption drum in an inverted state; and an uppercarrier for receiving and moving the inverted unit cells from the tableto magazines.

In addition, a suction unit having one or more suction holes formed inthe longitudinal direction parallel to the rotation shaft of theadsorption drum may be formed on the circumferential surface of theadsorption drum.

In addition, the table may be provided with a block for limiting theposition of the unit cell on the top surface of the table as the blockcontacts with an end portion of the unit cell.

In addition, the upper carrier may include: a body unit parallel to therotation shaft of the adsorption drum and located on the table toreciprocate in the longitudinal direction; and a first adsorption unitand a second adsorption unit disposed on both longitudinal sides of thebody unit.

In addition, when the body unit reciprocates in the longitudinaldirection, any one of the first adsorption unit and the secondadsorption unit may adsorb the inverted unit cell positioned on thetable, and another one of the first adsorption unit and the secondadsorption unit may transfer the inverted unit cell to the magazine.

In addition, the stacking device may include: a floor for preparing theunit cell at a first position, the anode cell at a second position toface the unit cell, the inverted unit cell at a third position, and thecathode cell at a fourth position to face the inverted unit cell; astage reciprocating between the unit cell and the anode cell and betweenthe inverted unit cell and the cathode cell; and one or more robot armsfor stacking a unit cell, an anode cell, an inverted unit cell, and acathode cell prepared at the first position to the fourth position inorder on the stage.

In addition, the stage may be alternately tilted at a predeterminedangle toward the first position, the second position, the thirdposition, and the fourth position.

In addition, the first position and the third position may be located onone side of a path along which the stage moves, and the second positionand the fourth position are located on the other side of the path alongwhich the stage moves.

In addition, the robot arms may be positioned between the first positionand the third position and between the second position and the fourthposition, respectively.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing a secondary battery manufacturingsystem for simplifying a process of manufacturing unit cells bylaminating and a process of forming an electrode assembly using the unitcells according to an embodiment of the present invention.

FIGS. 2 and 3 are exemplary views showing a unit cell forming deviceprovided in the secondary battery manufacturing system for simplifying aprocess of manufacturing unit cells by laminating and a process offorming an electrode assembly using the unit cells of FIG. 1.

FIG. 4 is an exemplary view showing an inverting device provided in thesecondary battery manufacturing system for simplifying a process ofmanufacturing unit cells by laminating and a process of forming anelectrode assembly using the unit cells of FIG. 1.

FIG. 5 is a flowchart illustrating the operation of the inverting deviceof FIG. 4.

FIGS. 6 to 12 are views showing the states of continuously invertingunit cells according to the flowchart of FIG. 5.

FIGS. 13 and 14 are exemplary views showing a stacking device providedin the secondary battery manufacturing system for simplifying a processof manufacturing unit cells by laminating and a process of forming anelectrode assembly using the unit cells of FIG. 1.

FIG. 15 is an exemplary view showing a stage provided in the stackingdevice of FIG. 13.

DESCRIPTION OF SYMBOLS

-   1000: Unit cell forming device-   1100: Guide-   1200: Anode cell cutter-   1300: Cathode cell cutter-   1401: First laminator-   1402: Second laminator-   1500: Unit cell cutter-   1600: Idle roller-   2000: Inverting device-   2100: Conveyor belt-   2200: Adsorption drum-   2210: Suction unit-   2211: Suction hole-   2300: Table-   2310: Block-   2400: Upper carrier-   2410: Body unit-   2420: First adsorption unit-   2430: Second adsorption unit-   M1: Magazine-   M2: Magazine-   3000: Stacking device-   3100: Floor-   3110: Path-   3200: Stage-   3210: Body unit-   3211: Wheel-   3212: Tilting seat unit-   3213: Hinge-   3214: Guide-   3215: Clamping unit-   3300: Robot arm-   P1: First position-   P2: Second position-   P3: Third position-   P4: Fourth position-   R1: Separator roll-   R2: Anode cell roll-   R3: Cathode cell roller-   U1: Unit cell-   U2: Inverted unit cell-   NC: Anode cell-   PC: Cathode cell

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Hereafter, a secondary battery manufacturing system for simplifying aprocess of manufacturing unit cells by laminating and a process offorming an electrode assembly using the unit cells according to anembodiment of the invention will be described with reference to theaccompanying drawings.

As shown in FIG. 1, a secondary battery manufacturing system forsimplifying a process of manufacturing unit cells by laminating and aprocess of forming an electrode assembly using the unit cells accordingto an embodiment of the present invention includes: a unit cell formingdevice 1000 for forming unit cells U1, in which a separator, an anodecell, a separator, a cathode cell, and a separator are stacked in order,from a separator roll R1, an anode cell roll R2, and a cathode cell rollR3, which are rolled; an inverting device 2000 for forming inverted unitcells U2, in which a separator, a cathode cell, a separator, an anodecell, and a separator are stacked in order, by inverting some of two ormore unit cells U1 formed by the unit cell forming device 1000; and astacking device 3000 for stacking a unit cell, an anode cell, aninverted unit cell, and a cathode cell in order.

The unit cell U1 has a structure of a unit full cell formed of aseparator, an anode cell, a separator, a cathode cell, and a separator.The anode cell is an electrode having a negative polarity, coated withan anode material on both sides, and the cathode cell is an electrodehaving a positive polarity, coated with a cathode material on bothsides. The inverted unit cell U2 has a structure of a unit full cellformed in order of a separator, a cathode cell, a separator, an anodecell, and a separator.

As shown in FIG. 2, the unit cell forming device 1000 includes: guides1100 for guiding the separator, the anode cell and the cathode cellunrolled from the separator roll R1, the anode cell roll R2, and thecathode cell roll R3 to be overlapped; an anode cell cutter 1200 forforming one or more unit anode cells by dividing the anode cell in aunit size, and cutting the anode cell to be arranged at appropriateintervals; a cathode cell cutter 1300 for forming one or more unitcathode cells by dividing the cathode cell in a unit size, and cuttingthe cathode cell to be arranged at appropriate intervals; a firstlaminator 1401 and a second laminator 1402 for stacking and integratingthe separator, the one or more unit anode cells arranged at appropriateintervals, the separator, the one or more unit cathode cells arranged atappropriate intervals, and the separator in order; and a unit cellcutter 1500 for cutting the separator, the one or more unit anode cellsarranged at appropriate intervals, the separator, the one or more unitcathode cells arranged at appropriate intervals, and the separatorintegrated by the first laminator 1401 and the second laminator 1402 ina unit cell U1 size.

When it is determined that the tension is small as deflection occurs inthe separator, the anode cell and the cathode cell unrolled from theseparator roll R1, the anode cell roll R2 and the cathode cell roll R3,the guides 1100 compensate for the deflection of the separator, theanode cell and the cathode cell by moving up, down, left and right. Acontrol unit or the like for controlling the operation of varioussensors and the guides 1000 may be provided to sense the deflection.

In the first laminator 1401, a separator, one or more unit anode cellsarranged at appropriate intervals, and a separator are stacked andintegrated in order. In the second laminator 1402, one or more unitcathode cells arranged at appropriate intervals and a separator arestacked and integrated in order on the integrated separator, one or moreunit anode cells arranged at appropriate intervals, and separator.

According to another embodiment, as shown in FIG. 3, in the firstlaminator 1401, a separator, one or more unit cathode cells arranged atappropriate intervals, and a separator are stacked and integrated inorder. In the second laminator 1402, one or more unit anode cellsarranged at appropriate intervals and a separator are stacked andintegrated in order under the integrated separator, one or more unitcathode cells arranged at appropriate intervals, and separator.

Referring to FIG. 2 again, an adhesive is applied on the surface of theseparator. The first laminator 1401 and the second laminator 1402generate heat and pressure to integrate the separator, the one or moreunit anode cells arranged at appropriate intervals, the separator, theone or more unit cathode cells arranged at appropriate intervals, andthe separator.

An idle roller 1600 for guiding the integrated separator, one or moreunit anode cells arranged at appropriate intervals, separator, one ormore unit cathode cells arranged at appropriate intervals, and separatorfrom the second laminator 1402 to the unit cell cutter 1500 is locatedbetween the second laminator 1402 and the unit cell cutter 1500. Theunit cell cutter 1500 cuts gap portions, where a unit anode cell or acathode cell does not exist, in the vertical direction. The unit cellcutter 1500 may be provided in a form having blades protruding from thetop and the bottom.

As shown in FIG. 4, the inverting device 2000 includes: a conveyor belt2100 continuously supplied with the unit cells U1 configuring a fullcell; an adsorption drum 2200 located on the top surface of the conveyorbelt 2100 to adsorb the unit cells U1; a table 2300 located at one sideon the top of the adsorption drum 2200 to receive the unit cells U1 fromthe adsorption drum 2200 in an inverted state; and an upper carrier 2400for receiving and moving the inverted unit cells U1 from the table 2300to the magazines M1 and M2.

The adsorption drum 2200 is manufactured in the form of a cylinder. Arotation shaft is located at the center of the adsorption drum 2200. Therotation shaft receives rotating force from a gear box located on theside surface of the adsorption drum 2200. One or more intake pipes areembedded in the adsorption drum 2200. A suction unit 2210 having one ormore suction holes 2211 formed in the width direction parallel to therotation shaft of the adsorption drum 2200 is formed on thecircumferential surface of the adsorption drum 2200. According to anembodiment, four suction units 2210 are formed on the circumferentialsurface of the adsorption drum 2200. The four suction units 2210 arearranged along the circumferential surface of the adsorption drum 2200at the intervals of 90 degrees.

According to another embodiment, in addition to the suction unit 2210,the adsorption drum 2200 may be provided with a clamp or a hand formomentarily gripping both longitudinal ends of the unit cell U1. Inaddition, the adsorption drum 2200 may be manufactured in the form of atriangular prism or a square prism, not in the form of a cylinder. Inparticular, the rotation shaft may be eccentric and does not passthrough the center of the adsorption drum 2200.

Meanwhile, an intake pipe is connected to each suction hole 2211 orconnected to the suction unit 2210. One or more intake pipes areconnected to a vacuum pump. Valves for adjusting the suction force ofthe unit cell U1 by the suction unit 2210 are mounted on one or moreintake pipes. Operation of the valves is controlled by a control valve.The control valve controls operation of the valves so that the suctionunit 2210 may adsorb the unit cell U1 or release adsorption of the unitcell U1 by logic, control map, formula or the like prepared in advance.In addition, rubber is applied on the rounded surface of the adsorptiondrum 2200. The unit cell U1 is pushed from the adsorption drum 2200 tothe table 2300 as the unit cell U1 is rubbed with the rubber.

The table 2300 is a plate parallel to the ground. The table 2300 isprovided with a block 2310 for limiting the position of the unit cell U1on the top surface of the table 2300 as the block contacts with an endportion of the unit cell U1. The unit cell U1 is separated from thetable 2300 and prevented from falling to the conveyor belt 2100 by theblock 2310. According to another embodiment, a guide may be provided onthe table 2300 to allow the unit cell U1 to be positioned at a rightposition.

The upper carrier 2400 includes a body unit 2410 parallel to therotation shaft of the adsorption drum 2200 and located on the table 2300to reciprocate in the longitudinal direction, and a first adsorptionunit 2420 and a second adsorption unit 2430 disposed on bothlongitudinal sides of the body unit 2410.

The body unit 2410 is manufactured in the form of a beam. A hanging unitof a ‘¬’ shape is provided on the body unit 2410, and a roller isprovided in the hanging unit. The hanging unit is hung so that theroller is seated on a rail located on the top of the conveyor belt 2100.A motor is provided in the roller. The roller is rotated by the motor,and the body unit 2410 reciprocates in the longitudinal direction. Thefirst adsorption unit 2420 and the second adsorption unit 2430 areconnected to a vacuum pump. The inverted unit cells U1 are adsorbed bythe suction force generated by the vacuum pump.

According to an embodiment, when the body unit 2410 reciprocates in thelongitudinal direction, any one of the first adsorption unit 2420 andthe second adsorption unit 2430 adsorbs the inverted unit cell U1positioned on the table 2300, and another one of the first adsorptionunit 2420 and the second adsorption unit 2430 transfers the invertedunit cell U1 to the magazine M1 or M2. That is, the first adsorptionunit 2420 and the second adsorption unit 2430 sequentially adsorbinverted unit cells U1 and sequentially transfer the unit cells U1 tothe magazines M1 and M2. The magazines M1 and M2 are arranged to besymmetrical to each other with respect to the conveyor belt 2100.

According to another embodiment, although the magazines M1 and M2 areseparately disposed with intervention of the conveyor belt 2100, theheight spaced apart from the ground or the separation distance from theconveyor belt 2100 may be different from each other.

FIG. 5 is a flowchart illustrating the operation of the inverting device2000. FIGS. 6 to 12 are views showing the states of continuouslyinverting unit cells U1 according to the flowchart of FIG. 5.

As shown in FIGS. 5 to 12, the operation of the inverting device 2000includes the steps of: arriving at an adsorption position, by any one ofone or more unit cells U1 carried by the conveyor belt 2100; adsorbingthe unit cell U1 arriving at the adsorption position, by the adsorptiondrum 2200; inverting the unit cell U1 adsorbed to the adsorption drum2200 while moving from the bottom of the adsorption drum 2200 close tothe conveyor belt 2100 to the top of the adsorption drum 2200 close tothe upper carrier 2400 according to rotation of the adsorption drum2200; transferring the unit cell U1 from the adsorption drum 2200 to thetable 2300 while the unit cell U1 is inverted; and receiving andtransferring the inverted unit cell U1 from the table 2300 to themagazine M1 or M2, by the upper carrier 2400.

As shown in FIG. 6, any one of the one or more unit cells U1 carried bythe conveyor belt 2100 is adsorbed to the adsorption drum 2200 throughthe step of arriving at an adsorption position and the adsorbing step.

As shown in FIG. 7, at the step of moving and inverting the unit cellU1, the unit cell U1 adsorbed to the adsorption drum 2200 as theadsorption drum 2200 rotates is moved from the bottom of the adsorptiondrum 2200 to the top of the adsorption drum 2200. At this point, anotherunit cell U1 arriving at the adsorption position is adsorbed to theadsorption drum 2200.

As shown in FIGS. 8 and 9, at the step of receiving and transferring theinverted unit cell U1 from the table 2300 to the magazine M1 or M2 bythe upper carrier 2400, the upper carrier 2400 moves in the longitudinaldirection, after the first adsorption unit 2420 provided at onelongitudinal side adsorbs the inverted unit cell U1, so that the firstadsorption unit 2420 may arrive at the magazine M1 or M2. When the firstadsorption part 2420 moves in the longitudinal direction to arrive atthe magazine M1 or M2, another unit cell U1 is inverted while movingfrom the bottom of the adsorption drum 2200 to the top of the adsorptiondrum 2200, and is transferred from the adsorption drum 2200 to the table2300.

As shown in FIG. 10, when the first adsorption unit 2420 arrives at themagazine M1 or M2, the second adsorption unit 2430 adsorbs another unitcell U1 that is inverted. After the second adsorption unit 2430 adsorbsanother unit cell U1 and the first adsorption unit 2420 transfers theunit cell U1 to the magazine M1 or M2, the upper carrier 2400 moves inthe longitudinal direction as shown in FIG. 10 so that the secondadsorption unit 2430 may move toward the other magazine M1 or M2arranged to be symmetrical to the magazine M1 or M2 with respect to theconveyor belt 2100. At this point, as the adsorption drum 2200 rotates,another inverted unit cell U1 adsorbed to the adsorption drum 2200 isinverted while moving from the bottom of the adsorption drum 2200 to thetop of the adsorption drum 2200, and is transferred from the adsorptiondrum 2200 to the table 2300.

As shown in FIG. 12, when the second adsorption unit 2430 arrives at theother magazine M1 or M2, the first adsorption unit 2420 adsorbs anotherinverted unit cell U1 positioned on the table 2300.

As described above, the adsorption drum 2200 repeatedly adsorbs andinverts unit cells U1 while rotating, and transfers the inverted unitcells U1 to the table 2300. The upper carrier 2400 moves the invertedunit cell U1 positioned on the table 2300 to any one of the twomagazines M1 and M2, and transfers the inverted unit cell U1 to one ofthe magazines M1 and M2 while repeatedly reciprocating in thelongitudinal direction.

Therefore, according to the inverting device 2000 of an embodiment ofthe present invention configured as described above, since a unit cellU1 adsorbed to the adsorption drum 2200 is inverted while moving fromthe bottom of the adsorption drum 2200 to the top of the adsorption drum2200, the unit cells U1 can be easily inverted.

Particularly, since inverted unit cells U1 are successively stacked onthe magazines M1 and M2, preparation of the inverted unit cells U1 formanufacturing a secondary battery is convenient.

As shown in FIG. 13, the stacking device 3000 includes: a floor 3100 forpreparing a unit cell U1 at a first position P1, an anode cell NC at asecond position P2 to face the unit cell U1, an inverted unit cell U2 ata third position P3, and a cathode cell PC at a fourth position P4 toface the inverted unit cell U2; a stage 3200 reciprocating between theunit cell U1 and the anode cell NC and between the inverted unit cell U2and the cathode cell PC; and one or more robot arms 3300 for stacking aunit cell, an anode cell, an inverted unit cell, and a cathode cellprepared at the first position P1 to the fourth position P4 in order onthe stage 3200.

The first position P1 and the third position P3 are located on one sideof a path 3110 along which the stage 3200 moves, and the second positionP2 and the fourth position P4 are located on the other side of the path3110 that is formed on the floor 3100 so that the stage 3200 may move.

The path 3110 is formed on the floor 3100 in the form of a straightline, a curved line, an ellipse or a circle. The first position P1, thesecond position P2, the third position P3 and the fourth position P4 arearranged to be perpendicular to the path 3110. As shown in FIG. 12, whenthe path 3110 is a straight line, the stage 3200 reciprocates betweenthe first position P1 and the second position P2 and between the thirdposition P3 and the fourth position P4 while moving forward or backward.As shown in FIG. 14, when the path 3110 is a rotation path of an ellipseor a circle, the first position P1 and the second position P2, and thethird position P3 and the fourth position P4 are repeatedly formed, andthe stage 3200 moves only in a specific direction along thecircumference.

FIG. 15 is an exemplary view showing the stage 3200. As shown in FIG.15, the stage 3200 is manufactured to be alternately tilted at apredetermined angle toward the first position P1, the second positionP2, the third position P3, and the fourth position P4. The stage 3200includes a body unit 3210 moving along the path 3110, and a tilting seatunit 3212 positioned on the top surface of the body unit 3210 and tiltedleft or right around a hinge 3213 parallel to the ground.

A wheel 3211 driven along the path 3110 and a driver for rotating thewheel 3211 are mounted on the body unit 3210. The tilting seat unit 3212is provided with a guide 3214 for seating a unit cell U1, an invertedunit cell U2, an anode cell NC and a cathode cell PC at right positions.The tilting seat unit 3212 is provided with a clamping unit 3215 forfixing the unit cell U1, the inverted unit cell U2, the anode cell NC,and the cathode cell PC seated on the tilting seat unit 3212.

Referring to FIG. 13 again, stacking the unit cell U1, the anode cellNC, the inverted unit cell U2, and the cathode cell PC on the stage 3200is accomplished by the robot arms 3300. The robot arms 3300 may bedisposed at one side of the first position P1, the second position P2,the third position P3 and the fourth position P4, respectively.According to another example, the robot arms 3300 may be disposedbetween the first position P1 and the third position P3 and between thesecond position P2 and the fourth position P4, respectively. In thiscase, the robot arms 3300 may move any one among the unit cell U1, theanode cell NC, the inverted unit cell U2, and the cathode cell PC to thestage 3200 while moving between the first position P1 and the thirdposition P3 and between the second position P2 and the fourth positionP4. When the path 3110 is a rotation path, the robot arm 3300 may bemounted on the stage 3200.

According to the secondary battery manufacturing system for simplifyinga process of manufacturing unit cells by laminating and a process offorming an electrode assembly using the unit cells according to anembodiment of the present invention configured as described above, theprocess of manufacturing an electrode assembly is simplified, and thedefect rate of the manufactured electrode assembly is lowered.

Particularly, since the unit cells U1 are manufactured throughlaminating, manufacturing the unit cells U1 is easy. In addition, sincea method of alternately stacking the unit cells U1 and electrode cellsmanufactured by laminating is selected as a method of forming anelectrode assembly, the process of preparing the unit cells U1 and theelectrode cells is simple, and the frequency of rework can be remarkablyreduced as defective electrodes are removed in advance in acorresponding preparation process. In addition, the unit cells U1 andthe electrode cells can be seated at right positions through the tiltedstage 3200 and the robot arms 3300. Ultimately, the defect rate of theelectrode assembly can be lowered.

According to the secondary battery manufacturing system for simplifyinga process of manufacturing unit cells by laminating and a process offorming an electrode assembly using the unit cells according to anembodiment of the present invention configured as described above, theprocess of manufacturing an electrode assembly is simplified, and thedefect rate of the manufactured electrode assembly is lowered.

Particularly, since the unit cells are manufactured through laminating,manufacturing the unit cells is easy. In addition, since a method ofalternately stacking the unit cells and electrode cells manufactured bylaminating is selected as a method of forming an electrode assembly, theprocess of preparing the unit cells and the electrode cells is simple,and the frequency of rework can be remarkably lowered as defectiveelectrodes are removed in advance in a corresponding preparationprocess.

In addition, the unit cells and the electrode cells can be seated atright positions through the tilted stage and the robot arms. Ultimately,the defect rate of the electrode assembly can be lowered.

What is claimed is:
 1. A secondary battery manufacturing system forsimplifying a process of manufacturing unit cells by laminating and aprocess of forming an electrode assembly using the unit cells, thesystem comprising: a unit cell forming device for the forming unitcells, in which a separator, an anode cell, a separator, a cathode cell,and a separator are stacked in order, from a separator roll, an anodecell roll, and a cathode cell roll, which are rolled; an invertingdevice for forming inverted unit cells, in which a separator, a cathodecell, a separator, an anode cell, and a separator are stacked in order,by inverting some of two or more unit cells formed by the unit cellforming device; and a stacking device for stacking a unit cell, an anodecell, an inverted unit cell, and a cathode cell in order, wherein theunit cell forming device forms the unit cells by stacking andintegrating a separator, an anode cell, and a separator in order, andthen stacking and integrating a cathode cell and a separator thereon,and the stacking device includes: a floor for preparing the unit cell ata first position, the anode cell at a second position to face the unitcell, the inverted unit cell at a third position, and the cathode cellat a fourth position to face the inverted unit cell; a stagereciprocating between the unit cell and the anode cell and between theinverted unit cell and the cathode cell; and one or more robot arms forstacking a unit cell, an anode cell, an inverted unit cell, and acathode cell prepared at the first position to the fourth position inorder on the stage.
 2. A secondary battery manufacturing system forsimplifying a process of manufacturing unit cells by laminating and aprocess of forming an electrode assembly using the unit cells, thesystem comprising: a unit cell forming device for the forming unitcells, in which a separator, an anode cell, a separator, a cathode cell,and a separator are stacked in order, from a separator roll, an anodecell roll, and a cathode cell roll, which are rolled; an invertingdevice for forming inverted unit cells, in which a separator, a cathodecell, a separator, an anode cell, and a separator are stacked in order,by inverting some of two or more unit cells formed by the unit cellforming device; and a stacking device for stacking a unit cell, an anodecell, an inverted unit cell, and a cathode cell in order, wherein theunit cell forming device forms the unit cells by stacking andintegrating a separator, a cathode cell, and a separator in order, andthen stacking and integrating an anode cell and a separator below, andthe stacking device includes: a floor for preparing the unit cell at afirst position, the anode cell at a second position to face the unitcell, the inverted unit cell at a third position, and the cathode cellat a fourth position to face the inverted unit cell; a stagereciprocating between the unit cell and the anode cell and between theinverted unit cell and the cathode cell; and one or more robot arms forstacking a unit cell, an anode cell, an inverted unit cell, and acathode cell prepared at the first position to the fourth position inorder on the stage.
 3. The system according to claim 1, wherein the unitcell forming device includes: guides for guiding the separator, theanode cell and the cathode cell unrolled from the separator roll, theanode cell roll, and the cathode cell roll to be overlapped; an anodecell cutter for forming unit anode cells by dividing the anode cell in aunit size, and cutting the anode cell to be arranged at appropriateintervals; a cathode cell cutter for forming unit cathode cells bydividing the cathode cell in a unit size, and cutting the cathode cellto be arranged at appropriate intervals; a first laminator and a secondlaminator for stacking and integrating the separator, the unit anodecells arranged at appropriate intervals, the separator, the unit cathodecells arranged at appropriate intervals, and the separator in order; anda unit cell cutter for cutting the separator, the unit anode cellsarranged at appropriate intervals, the separator, the unit cathode cellsarranged at appropriate intervals, and the separator integrated by thefirst laminator and the second laminator in a unit cell size.
 4. Thesystem according to claim 3, wherein an idle roller for guiding theintegrated separator, unit anode cells arranged at appropriateintervals, separator, unit cathode cells arranged at appropriateintervals, and separator from the second laminator to the unit cellcutter is located between the second laminator and the unit cell cutter.5. The system according to claim 1, wherein the inverting deviceincludes: a conveyor belt continuously supplied with the unit cells; anadsorption drum located on a top surface of the conveyor belt to adsorbthe unit cells; a table located at one side on a top of the adsorptiondrum to receive the unit cells from the adsorption drum in an invertedstate; and an upper carrier for receiving and moving the inverted unitcells from the table to magazines.
 6. The system according to claim 5,wherein a suction unit having one or more suction holes formed in alongitudinal direction parallel to a rotation shaft of the adsorptiondrum is formed on a circumferential surface of the adsorption drum. 7.The system according to claim 5, wherein the table is provided with ablock for limiting a position of the unit cell on a top surface of thetable as the block contacts with an end portion of the unit cell.
 8. Thesystem according to claim 5, wherein the upper carrier includes: a bodyunit parallel to a rotation shaft of the adsorption drum and located onthe table to reciprocate in the longitudinal direction; and a firstadsorption unit and a second adsorption unit disposed on bothlongitudinal sides of the body unit.
 9. The system according to claim 8,wherein when the body unit reciprocates in the longitudinal direction,any one of the first adsorption unit and the second adsorption unitadsorbs the inverted unit cell positioned on the table, and another oneof the first adsorption unit and the second adsorption unit transfersthe inverted unit cell to the magazine.
 10. The system according toclaim 1, wherein the stage can be alternately tilted at a predeterminedangle toward the first position, the second position, the thirdposition, and the fourth position.
 11. The system according to claim 1,wherein the first position and the third position are located on oneside of a path along which the stage moves, and the second position andthe fourth position are located on the other side of the path alongwhich the stage moves.
 12. The system according to claim 1, wherein therobot arms are positioned between the first position and the thirdposition and between the second position and the fourth position,respectively.
 13. The system according to claim 2, wherein the unit cellforming device includes: guides for guiding the separator, the anodecell and the cathode cell unrolled from the separator roll, the anodecell roll, and the cathode cell roll to be overlapped; an anode cellcutter for forming unit anode cells by dividing the anode cell in a unitsize, and cutting the anode cell to be arranged at appropriateintervals; a cathode cell cutter for forming unit cathode cells bydividing the cathode cell in a unit size, and cutting the cathode cellto be arranged at appropriate intervals; a first laminator and a secondlaminator for stacking and integrating the separator, the unit anodecells arranged at appropriate intervals, the separator, the unit cathodecells arranged at appropriate intervals, and the separator in order; anda unit cell cutter for cutting the separator, the unit anode cellsarranged at appropriate intervals, the separator, the unit cathode cellsarranged at appropriate intervals, and the separator integrated by thefirst laminator and the second laminator in a unit cell size.
 14. Thesystem according to claim 13, wherein an idle roller for guiding theintegrated separator, unit anode cells arranged at appropriateintervals, separator, unit cathode cells arranged at appropriateintervals, and separator from the second laminator to the unit cellcutter is located between the second laminator and the unit cell cutter.15. The system according to claim 2, wherein the inverting deviceincludes: a conveyor belt continuously supplied with the unit cells; anadsorption drum located on a top surface of the conveyor belt to adsorbthe unit cells; a table located at one side on a top of the adsorptiondrum to receive the unit cells from the adsorption drum in an invertedstate; and an upper carrier for receiving and moving the inverted unitcells from the table to magazines.
 16. The system according to claim 15,wherein a suction unit having one or more suction holes formed in alongitudinal direction parallel to a rotation shaft of the adsorptiondrum is formed on a circumferential surface of the adsorption drum. 17.The system according to claim 15, wherein the table is provided with ablock for limiting a position of the unit cell on a top surface of thetable as the block contacts with an end portion of the unit cell. 18.The system according to claim 2, wherein the stage can be alternatelytilted at a predetermined angle toward the first position, the secondposition, the third position, and the fourth position.
 19. The systemaccording to claim 2, wherein the first position and the third positionare located on one side of a path along which the stage moves, and thesecond position and the fourth position are located on the other side ofthe path along which the stage moves.
 20. The system according to claim2, wherein the robot arms are positioned between the first position andthe third position and between the second position and the fourthposition, respectively.